Quantum physics has then been decisive in elucidating the value of the elementary frequency of the pre-exponential factor, considered by Eyring himself as his main contribution. In fact, as suggested in [1]}, the TST is more a compilation of notions scattered in the previous literature than a real novelty and Eyring acknowledged that his formulation has certain features in common with a number of previous treatments [2]}. In particular, the identity between the equation of Arrhenius and that derived from the TST is clear when giving to the pre-exponential factor a configurational meaning [3]}.
